问题 选择题

上个世纪90年代末,某国中西部出现了罕见的灾害天气,导致该地区玉米产量比预计下降了53%,造成玉米价格大幅度上升。玉米价格的上升,不仅造成玉米需求量小幅下降,还造成小麦需求上升。这说明 [ ]

A.玉米的需求弹性较小,且玉米和小麦是替代商品

B.玉米的需求弹性较大,且玉米和小麦是替代商品

C.玉米的需求弹性较小,且玉米和小麦是互补商品

D.玉米的需求弹性较大,且玉米和小麦是互补商品

答案

答案:A

阅读理解

Science can’t explain the power of pets, but many studies have shown that the company of pets can help lower blood pressure and raise chances of recovering from a heart attack, reduce loneliness and spread all-round good cheer.

Any owner will tell you how much joy a pet brings. For some, an animal provides more comfort than a husband/wife. A 2002 study by Karen Allen of the State University of New York measured stress (紧张) levels and blood pressure in people ---half of them pet owners ---while they performed 5 minutes of mental arithmetic (算术) or held a hand in ice water. Subjects completed the tasks alone, with a husband/wife, a close friend or with a pet. People with pets did it best. Those tested with their animal friends had smaller change in blood pressure and returned most quickly to baseline heart rates. With pets in the room, people also made fewer math mistakes than when doing in front of other companions. It seems people feel more relaxed (放松)around pets, says Allen, who thinks it may be because pets don’t judge.

A study reported last fall suggests that having a pet dog not only raises your spirits but may also have an effect on your eating habits. Researchers at Northwestern Memorial Hospital spent a year studying 36 fat people and their equally fat dogs on diet-and-exercise programs; a separate group of 56 people without pets were put on a diet program. On average, people lost about I1 pounds, or 5% of their body weight. Their dogs did even better, losing an average of 12 pounds, more than 15% of their body weight. Dog owners didn’t lose any more weight than those without dogs but, say researchers, got more exercise overall---mostly with their dogs --- and found it worth doing.

小题1:What does the text mainly discuss?

A.What pets bring to their owners.

B.How pets help people calm down.

C.People’s opinions of keeping pets.

D.Pet’s value in medical research.小题2:We learn from the text that a person with heart disease has a better chance of getting well if _____.

A.he has a pet companion

B.he has less stress of work

C.he often does mental arithmetic

D.he is taken care of by his family小题3:According to Allen, why did the people do better with pets around when facing stressful tasks?

A.They have lower blood pressure.

B.They become more patient.

C.They are less nervous.

D.They are in higher spirits.

单项选择题